title: The effect of exercise on plasma concentrations of inflammatory markers in normal and previously laminitic ponies.
abstract: BACKGROUND
  The mechanisms underlying predisposition to pasture-associated laminitis remain unclear; chronic inflammation is implicated, and this may be exacerbated by physical inactivity.
  
  
  OBJECTIVE
  To determine whether exercise affects the inflammatory profile of normal and previously laminitic ponies.
  
  
  METHODS
  Prospective case-control study.
  
  
  METHODS
  The short (1 day) and longer term (14 days) effects of low intensity (10 min walking and 5 min trotting) exercise on plasma inflammatory marker concentrations in normal (NL) and previously laminitic (PL) nonobese ponies (n = 6/group) was determined. Plasma concentrations of TNF-α, serum amyloid A (SAA), haptoglobin, insulin, adiponectin and fibrinogen were assayed by validated/standard methods. Data were analysed using a linear mixed effects model.
  
  
  RESULTS
  Before exercise, plasma [adiponectin] was significantly (P = 0.0001) lower in PL (mean ± s.d. 2.4 ± 0.1 ng/l) than in NL (4.03 ± 0.2 ng/l), but exercise had no effect. Previous laminitis and exercise had no effect on plasma [TNF-α] or [fibrinogen]. Serum amyloid A concentrations in all ponies were significantly (P = 0.00001) reduced after longer term exercise compared to Day 1 values. Plasma [haptoglobin] was significantly (P = 0.00001) higher in PL compared to NL on Day 1. This difference was no longer apparent after longer term exercise, such that [haptoglobin] in PL had decreased to concentrations similar to NL. Following short-term exercise, all ponies had an initial decrease in serum [insulin] immediately after exercise, followed by an increase peaking 10 min after exercise cessation, before returning to pre-exercise values. On Day 14 these fluctuations were significantly (P = 0.001) reduced in all ponies.
  
  
  CONCLUSIONS
  Fourteen days of low intensity exercise significantly decreased [SAA] in all ponies and plasma [haptoglobin] in PL such that it was no longer increased compared to NL. Regular low intensity exercise appears to have an anti-inflammatory effect, which is possibly greater in PL and so may be beneficial in reducing this putative risk factor in pasture-associated laminitis.
authors.affiliation: Royal Veterinary College, London, UK.
authors.forename: N J
authors.initials: NJ
authors.lastname: Menzies-Gow
authors.forename: H
authors.initials: H
authors.lastname: Wray
authors.forename: S R
authors.initials: SR
authors.lastname: Bailey
authors.forename: P A
authors.initials: PA
authors.lastname: Harris
authors.forename: J
authors.initials: J
authors.lastname: Elliott
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D005260:Female; D005534:Foot Diseases / Q000097:blood / Q000378:metabolism / Q000662:veterinary; D005786:Gene Expression Regulation / Q000502:physiology; D006724:Hoof and Claw / Q000473:pathology; D006734:Horse Diseases / Q000097:blood / Q000378:metabolism; D006736:Horses / Q000097:blood* / Q000502:physiology*; D007249:Inflammation / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*
chemical_list: D015415:Biomarkers
keywords: haptoglobin; horse; insulin; laminitis; serum amyloid A